JP3429897B2 - Pellicle manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used to protect semiconductors such as LSIs and VLSIs, or to prevent dust in the exposure method using light of 500 nm or less, which is used as a dust shield when manufacturing liquid crystal display boards. and a method of manufacturing the Periku Le.

[0002]

2. Description of the Related Art In the production of semiconductor devices such as LSI and VLSI, or liquid crystal display plates, a semiconductor wafer or liquid crystal display plate is irradiated with light to form a pattern. If dust is attached, it absorbs light or bends the light, so the transferred pattern is deformed, the edges are sharp, and the white background is black and dirty, so However, there is a problem in that the quality and appearance are impaired, and the performance and manufacturing yield of semiconductor devices, liquid crystal display panels, and the like are reduced. For this reason, these operations are usually performed in a clean room, but it is difficult to keep the exposure master always clean even in this clean room. There is a method of sticking a pellicle that passes through well.

In this case, since dust does not directly adhere to the surface of the exposure original plate but adheres to the pellicle, if the focus is aligned with the pattern of the exposure original plate during lithography,
Dust on the pellicle has nothing to do with transfer, but this pellicle film has a thin film of cellulose-based polymers such as nitrocellulose, cellulose acetate, and cellulose propionate that pass ultraviolet rays well, and amorphous fluoropolymers, and aluminum. , A pellicle frame made of a material such as stainless steel or plastics, is coated with a good solvent for the pellicle film on the upper part of the pellicle frame, and air-dried for adhesion (see JP-A-58-219023), or an acrylic resin or Although it is adhered with an adhesive such as an epoxy resin (see U.S. Pat. No. 4,861,402, Japanese Patent Publication No. 63-27707), a polybutene resin, a polybutene resin, and poly Providing an adhesive layer made of vinyl acetate, acrylic resin, etc.
Further, it is also known that the surface of this adhesive layer is bonded with a separator for the purpose of protecting the adhesive layer.

[0004]

However, when the pellicle is used, it is the pellicle film that is directly irradiated with the exposure light source (ultraviolet rays such as g-line and i-line, or excimer laser beam). Since the adhesive that fixes the film to the pellicle frame may also be exposed to part of the exposure light source, this adhesive requires light resistance, and this adhesive requires a pellicle film of several microns. Since it is necessary to bond the pellicle in a stretched state at all times, it is an important material for the performance of the pellicle. However, the acrylic adhesives and epoxy adhesives used here have insufficient adhesive strength, or the adhesive area is not constant, resulting in lack of reliability such as wrinkles. These adhesives are severely deteriorated by the exposure light source,
When used to a certain extent, the adhesive solidifies and decomposes, which becomes a source of dust, and wrinkles easily occur in the film due to changes in the tension of the pellicle film, which causes the film to peel from the frame or crack.

Therefore, the present inventors have proposed a method of adhering these deficiencies by adhering a pellicle film made of a fluorine-based organic material to a pellicle frame with an adhesive made of a fluorine-based organic material (JP-A-6-67409). (See Japanese Patent Laid-Open Publication No. 2003-242242), which assumes that the pellicle film material and the adhesive have the same or similar structure, and when this is heated to around the glass transition temperature or higher, the pellicle film is firmly attached to the pellicle frame by the adhesive. It is based on the finding that it adheres, but in this case if this adhesion is heated above the glass transition temperature of the polymer, wrinkles and distortions tend to occur in the pellicle film, and in order to prevent this, this heating It has been found that there is a disadvantage that the adhesive strength becomes insufficient when the temperature is set to the glass transition temperature or lower.

[0006]

Means for Solving the Problems The present invention relates to a process for the preparation of Periku Le solving such a disadvantage, which is applied an adhesive having a pellicle film equivalent or similar structure on the pellicle frame After forming the adhesive layer,
A pellicle film containing a solvent in which a pellicle film-forming polymer is dissolved is adhered to the pellicle film when the pellicle film is formed, and the pellicle film and the pellicle frame are adhered to each other by heating at a temperature not higher than the glass transition temperature of the polymer. To do.

That is, the present inventors have conducted various studies on a method of obtaining a pellicle film having a good appearance without wrinkles or distortions. As a result, the adhesion between the pellicle film and the pellicle frame is equal to or better than that of the pellicle film. Although it is possible to firmly bond the pellicle film and the pellicle frame by bonding with an adhesive having a structure similar to
In order to make it have a sufficient adhesive strength, it is necessary to heat it above the glass transition temperature of the pellicle film-forming polymer. In this case, wrinkles and distortions occur in the pellicle film, which makes the appearance unsightly. However, if this pellicle film contains the solvent used during the production as a residual solvent, the pellicle film and the pellicle frame are It was found that the adhesive can be adhered as a material having sufficiently high strength even by heating below the glass transition temperature of the pellicle film-forming polymer. Therefore, according to this, the pellicle film and the pellicle frame are adhered with high strength,
The present invention has been completed by confirming that a pellicle without wrinkles or distortion can be easily obtained. This will be described in more detail below.

[0008]

According to the pellicle manufacturing method of the present invention, an adhesive having a structure similar to or similar to the pellicle film is applied on the pellicle frame to form an adhesive layer on the pellicle frame, as described above. The pellicle film containing the solvent in which the pellicle film-forming polymer is dissolved as a residual solvent is brought into close contact, and these are heated to a temperature not higher than the glass transition temperature of the pellicle film-forming polymer to bond the pellicle film and the pellicle frame. According to this, even if the heating temperature is lower than the glass transition temperature of the polymer, the pellicle film contains the residual solvent, so that the pellicle film and the pellicle frame can be firmly bonded. Since this temperature is below the glass transition temperature of this polymer, the pellicle can be obtained without wrinkles and distortion. Interest property can be given.

The pellicle film that constitutes the pellicle of the present invention may be any conventionally known one, and therefore, a pellicle membrane such as nitrocellulose or cellulose acetate may be used.
The present inventors have previously proposed polytrimethylvinylsilane (see JP-A-2-230245), a pullulan compound (see JP-A-3-210561), and an amorphous fluoropolymer (see JP-A-4-23045). No. 104155), silicone-modified polyvinyl alcohol (see Japanese Patent Application Laid-Open No. 4-241351), and the like, but it is preferable to use an amorphous fluoropolymer. This amorphous fluoropolymer may be obtained by copolymerizing tetrafluoroethylene and a fluoromonomer having a cyclic perfluoroether group, which is commercially available Teflon AF (manufactured by DuPont, USA). Trade name) and Cytop [trade name of Asahi Glass Co., Ltd.].

This pellicle film is prepared by dissolving these film materials in a concentration of 3 to 10% by weight using a solvent, and then applying this solution onto a silicon substrate or a glass substrate by a solution caster method using a spin coater or a knife coater. It can be obtained by forming a film, but the thickness of this film is 0.1 to 10 μm, preferably from the balance of mechanical strength and transmittance.
The thickness may be 0.5 to 5 μm. However, since the pellicle film of the present invention needs to contain this solvent as a residual solvent as described above, the pellicle film of the present invention controls the heat treatment conditions when forming the pellicle film to allow this solvent to remain. .

Any method can be used for the residual solvent. However, if the solvent is a mixed solvent having different boiling points, the residual solvent amount can be controlled by controlling the mixing ratio and the heat treatment concentration. It can be controlled arbitrarily. The amount of the residual solvent can be measured by the change in weight. Specifically, the membrane is weighed in a weighing bottle, and the weight of the sample is measured in the bottle under appropriate conditions such as 200 ° C. and 4 ° C.
After treating with Torr for 1 hour and drying, the weight may be measured again and the solvent content may be determined from the difference. However, when the residual solvent amount at the time of peeling the film exceeds 70% by weight, the film stretches or breaks. On the other hand, when the residual solvent amount is less than 1% by weight, sufficient adhesive strength can be obtained by heat treatment below the glass transition temperature. Since it cannot be obtained, it is necessary to set this in the range of 1 to 70% by weight, and this preferable range is set to 10 to 60% by weight.

The pellicle film containing the residual solvent thus obtained is adhered to the pellicle frame, and this pellicle frame may be a known one, and therefore, it can be made of aluminum, stainless steel, polyethylene, polypropylene. It may be made of plastic such as, but this is generally made of anodized aluminum of 120 mm square.
The adhesive used here may be made of a polymer having a structure similar to or similar to the pellicle film proposed by the present inventors, but this pellicle film is made of amorphous fluorine. When the solvent is a polymer, the solvent is a commercially available organic fluorine compound, Fluorinert FC-75 [trade name of Sumitomo 3M Limited], C
T solv 180 to 210 [trade name of Asahi Glass Co., Ltd.] may be used.

In the method for producing a pellicle of the present invention, the pellicle film containing the residual solvent produced by the above-mentioned method is coated with a polymer having a structure similar to or similar to that of the pellicle film as an adhesive to form an adhesive layer. The pellicle frame and the pellicle frame are adhered to each other and heated to bond the pellicle film to the pellicle frame. In this case, since the pellicle film contains residual solvent, this heating is not performed. Even if the glass transition temperature of the pellicle film-forming polymer is not higher than the glass transition temperature, the pellicle film and the pellicle frame can be bonded to each other with a strong strength, and thus the pellicle film can be made free from wrinkles and distortion.

[0014]

EXAMPLES Examples and comparative examples of the present invention will be given below.
The adhesive strength between the pellicle film and the pellicle frame is the result of measurement by the following method. (Measurement of adhesive strength) An air blower with a nozzle diameter of 1 mm and an air pressure of 6 kg / cm ² was installed at a position 5 mm from the pellicle frame and 10 mm from the membrane, and a pressure of 6 kg / cm ² from this air blow. Since air is blown with the film and the film does not separate from the frame at this time, and the film itself is torn, it is considered to be a good product, so this was defined as the film strength or more.

Example 1 Perfluoro (butenyl vinyl ether) polymer / Cytop CTXS type, glass transition temperature 108 ° C., [Asahi Glass Co., Ltd. trade name] was used as its solvent CT solv 180 [Asahi Glass Co., Ltd. trade name. ] And CT solv 210 (trade name of Asahi Glass Co., Ltd.) dissolved in a mixed solvent of 5: 1 (weight ratio, the same applies hereinafter) to prepare a solution having a concentration of 3% (concentration indicates weight%, the same applies below). did. This solution is then 200 mm in diameter and 3 mm thick
A 0.84 μm-thick transparent film was formed on the surface-polished quartz substrate surface using a spin coater and dried at 180 ° C for 3 minutes to form a pellicle film. The residual solvent content of this film was measured. The result was 25% by weight.

On the other hand, the above-mentioned Cytop CTXA type (above) was used as a solvent CT solv 1 on the upper surface of an anodized aluminum frame of 120 mm square as a pellicle frame.
Fluorine polymer adhesive with a concentration of 10% dissolved in 80 (described above) was applied and dried at 150 ° C for 1 hour to form an adhesive layer with a thickness of 0.2 mm, and then the pellicle film obtained above was framed. Then, the pellicle film was bonded to the pellicle frame by heating at 100 ° C for 25 minutes with an infrared lamp, and the excess film was removed to make a pellicle. The pellicle had a good appearance without wrinkles or distortion.

Example 2 Teflon A, a copolymer of tetrafluoroethylene and perfluoro (2,2-dimethyl-1,3-dioxole)
F1600, glass transition temperature 160 ° C., [trade name of DuPont USA] as its solvent Fluorinert FC-75 [trade name of Sumitomo 3M Ltd.] and solvent Fluorinert FC-70
It was dissolved in a 5: 1 mixed solvent of [trade name of Sumitomo 3M Ltd.] to prepare a solution having a concentration of 2%. Then, this solution was applied to the surface of a quartz substrate with a diameter of 200 mm and a thickness of 3 mm.
A transparent film having a film thickness of 0.84 μm was formed using a spin coater and dried at 180 ° C. for 3 minutes to form a pellicle film. The residual solvent content of this film was 27% by weight as a result of the measurement.

On the other hand, the above-mentioned Teflon AF1600 (above) was used as the solvent Fluorinert F on the upper surface of a 120 mm square aluminum frame which had been subjected to alumite treatment as a pellicle frame.
A fluoropolymer adhesive having a concentration of 10% dissolved in C-75 (described above) was applied and dried at 150 ° C for 1 hour to form an adhesive layer having a thickness of 0.2 mm. Then, the pellicle obtained above was applied to this. After the film is attached to the frame, it is exposed to an infrared lamp for 25 minutes at 150 ° C.
And heat it to bond the pellicle film and pellicle frame together.
When the pellicle was made by removing the extra film, the adhesive strength of the pellicle was higher than the film strength, and the pellicle had a good appearance without wrinkles or distortion.

Comparative Example 1 Cytop CTXS type as the amorphous fluoropolymer used in Example 1, glass transition temperature 108 ° C. (previously mentioned) was dissolved in its solvent CT solv 180 (previously mentioned) to give a concentration of 3
% Solution was prepared, and a 0.84 μm-thick transparent film was formed on the surface-polished quartz substrate surface with a diameter of 200 mm and a thickness of 3 mm using a spin coater and dried at 180 ° C. for 15 minutes. When a pellicle film was formed, the residual solvent content of this film was long to dry, so the measurement result was 0.7% by weight.
And became less.

On the other hand, the above polymer, CYTOP CTXA type (above) was used as a solvent CT on the upper surface of an alumite-treated 120 mm square aluminum frame as a pellicle frame.
Apply 10% concentration of fluoropolymer adhesive dissolved in solv180 (above) and dry at 150 ℃ for 1 hour to obtain a thickness of 0.2mm.
After forming the adhesive layer of 1., adhere the pellicle film obtained above to the frame, and infra red lamp for 100 minutes for 100 minutes.
When the pellicle film and the pellicle frame were bonded by heating to ℃ and the excess film was removed to make a pellicle, this product had a good appearance without wrinkles and distortion, but the residual solvent of the pellicle film However, the pellicle film was peeled off by air blow because the adhesive strength was insufficient because it was as small as 0.7% by weight.

Comparative Example 2 The CYTOP CTXS type as the amorphous fluorine-based polymer used in Example 1 and the glass transition temperature of 108 ° C. (mentioned above) were dissolved in its solvent CT solv 180 (described above) to give a concentration of 3
% Solution was prepared, and a 0.84 μm-thick transparent film was formed on the surface-polished quartz substrate surface with a diameter of 200 mm and a thickness of 3 mm using a spin coater and dried at 180 ° C. for 15 minutes. When a pellicle film was formed, the residual solvent content of this film was as low as 0.6% by weight as a result of measurement.

On the other hand, the above polymer, CYTOP CTXA type (above) was used as a solvent CT on the upper surface of an alumite-treated 120 mm square aluminum frame as a pellicle frame.
Apply 10% concentration of fluoropolymer adhesive dissolved in solv180 (above) and dry at 150 ℃ for 1 hour to obtain a thickness of 0.2mm.
After forming the adhesive layer of 1., the pellicle film obtained above was adhered to the frame, and then 120 minutes with an infrared lamp for 120 minutes.
When the pellicle film and the pellicle frame were bonded to each other by heating at 0 ° C. and the excess film was removed to form a pellicle, the pellicle had cracks along the frame and the appearance was poor.

Comparative Example 3 Cytop CTXS type as the amorphous fluoropolymer used in Example 1, glass transition temperature of 108 ° C. (supra), its solvent CT solv 180 (supra) and solvent CT sol.
v Concentrate 3% by dissolving in 1: 5 mixed solvent of 210 (supra)
A solution of 200 mm in diameter and 3 in thickness was prepared.
A transparent film with a thickness of 0.84 μm was formed on a quartz substrate surface with a surface polishing of mm using a spin coater and dried at 160 ° C for 5 minutes to form a pellicle film. The residual solvent content of this film was measured. The result was 82% by weight.

On the other hand, the above polymer, CYTOP CTXA type (above) was used as a solvent CT on the upper surface of an alumite-treated 120 mm square aluminum frame as a pellicle frame.
Apply 10% concentration of fluoropolymer adhesive dissolved in solv180 (above) and dry at 150 ℃ for 1 hour to obtain a thickness of 0.2mm.
After forming the adhesive layer of 1., the pellicle film obtained above was adhered to the frame, and then the infrared light was used for 105 minutes for 105 minutes.
When the pellicle film and the pellicle frame were adhered to each other by heating at 0 ° C. and the excess film was removed to make a pellicle, the pellicle film had slack, resulting in a poor appearance.

[0025]

According to the method for producing a pellicle of the present invention, a pellicle film contains a residual solvent, and a pellicle frame having an adhesive layer using a solvent having a structure similar to or similar to that of the pellicle film as an adhesive. The pellicle film and the pellicle frame are adhered to each other by heating them to a temperature below the glass transition temperature of the pellicle film-forming polymer. The pellicle has strong adhesive strength and is free from wrinkles and distortion. The advantage is afforded.

Front page continuation (72) Inventor Shirasaki Akira 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd., Institute for Precision Materials (72) Inventor Aihiko Nagata 2-13, Isobe, Gunma Prefecture No. 1 Shin-Etsu Chemical Co., Ltd., Precision Materials Research Laboratory (72) Inventor Shu Kashida 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd. (72) Inventor Yoshihiro Kubota 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd. Precision Materials Research Laboratory (56) References JP-A-6-67409 (JP, A) JP-A-4-369650 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F 1/14

Claims (3)

(57) [Claims] 1. A pellicle on a frame after the adhesive having a pellicle film equivalent or similar structure is applied to form an adhesive layer, a solvent residual solvent dissolving the pellicle film forming polymer during pellicle film A method for producing a pellicle, wherein the pellicle film contained as described above is adhered, and the pellicle film and the pellicle frame are bonded by heating at a temperature not higher than the glass transition temperature of the polymer. 2. A pellicle residual solvent amount in the film, method of manufacturing a pellicle as claimed in claim 1 which is 1～70Wt% relative pellicle film. 3. A pellicle membrane and adhesive, method of manufacturing a pellicle as claimed in claim 1 which is amorphous fluoropolymer.